Mecinus pascuorum (Gyllenhal)

Caldara, Roberto & Fogato, Valter, 2013, Systematics of the weevil genus <i> Mecinus </ i> Germar, 1821 (Coleoptera: Curculionidae). I. Taxonomic treatment of the species, Zootaxa 3654 (1), pp. 1-105 : 10-12

1. Mecinus pascuorum (Gyllenhal)

Figs 1 , 43–44 , 98, 105 , 108 , 144 , 157

Rhynchaenus pascuorum Gyllenhal, 1813: 124 .

Gymnetron pascuorum (Gyllenhal) . Gyllenhal, 1838: 744. H. Brisout de Barneville, 1862: 629. Desbrochers des Loges, 1893: 41. Rey, 1894: 74. Reitter, 1907: 20; 1916: 227. Hustache, 1931: 410. 419. Hoffmann, 1958: 1279, 1289. Smreczyṅski, 1976: 31. Lohse & Tischler, 1983: 267.

Mecinus pascuorum (Gyllenhal) . Caldara, 2001: 183.

Gymnetron nanum Dejean, 1836: 327 (nomen nudum).

Gymnetron bicolor Gyllenhal, 1838: 745 . Desbrochers des Loges, 1893: 42. Reitter, 1907: 21; 1916: 227. Hustache, 1931: 419. Hoffmann, 1958: 1289.

Gymnetron areolatum Betta, 1857: 61 . Caldara & Colonnelli, 2012: 90.

Gymnetron marshalli Donisthorpe, 1943: 45 . Morris, 1989: 25.

Gymnetron pascuorum var. setarium Desbrochers des Loges, 1893: 42 , 65. Rey, 1894: 74. Hoffmann, 1958: 1291 (infrasubspecific name).

Gymnetron pascuorum var. uniforme Desbrochers des Loges, 1893: 42 (infrasubspecific name).

Gymnetron pascuorum var. fuscicrum Rey, 1894: 74 (infrasubspecific name).

Gymnetron pascuorum ab. lancerotense Uyttenboogaart, 1934 : 166 (infrasubspecific name).

Gymnetron pascuorum var. testaceum Hoffmann, 1958: 1291 (infrasubspecific name).

Gymnetron pascuorum var. apicale Hoffmann, 1958: 1291 (infrasubspecific name).

Type locality. Sweden .

Type series. This species was described from female specimens with the following diagnosis: typical form “niger, griseo-pubescens, plaga elytrorum, antennarum basi tibiisque ferrugineis, rostrum longissimo tenui”; var b: “elytris nigris immaculatis”. In Gyllenhal's collection ( UZIU) we have examined 31 male and female specimens considered to be “historical specimens”. Based on the original description we have designated a female labelled “Udd / g / Uppsala Univ. Zool. Mus., Gyllenhals saml Type nr. 1263” as lectotype and the other 30 specimens as paralectotypes.

Synonyms. Gymnetron bicolor was described from specimens from Tauria (Crimea). We examined one of them labelled “Tauria, Steven / Typus” (female, lectotype here designated), which corresponded well with the original description. It is only a specimen of M. pascuorum with reddish elytra.

Gymnetron areolatum was described by Betta from specimens from Lombardy (northern Italy) no longer available. According to the original description Caldara & Colonnelli (2012) designated the neotype of this species and synonymized it with M. pascuorum .

Gymnetron marshalli Donisthorpe was placed in synonymy with M. pascuorum by Morris (1989) based on the examination of the types.

Gymnetron nanum is a nomen nudum and therefore unavailable according to Art. 12.1 of ICZN (1999).

The varieties setarius and uniformis described by Desbrochers des Loges, fuscicrus described by Rey, testaceus and apicalis described by Hoffmann and the aberration lancerotensis described by Uyttenboogaart are unequivocally considered as infrasubspecific taxa (ICZN 1999 Art. 45.6.1) by their authors and therefore all of these names are unavailable (ICZN 1999 Art. 45.5).

Redescription. Male. Length 1.5 mm. Body: short, oval, stout ( Fig. 1 ). Rostrum: black with reddish apex, moderately long (Rl/Pl 0.83), subcylindrical; in lateral view moderately curved, slightly narrowing in apical half ( Fig. 43 ); in dorsal view with subparallel sides, with slightly visible scrobes, distinctly striate-punctured to proximity of apex, then smooth and shining, in basal half with recumbent, sparse, greyish, long (l/w 7–10), setalike scales. Head: frons as wide as rostrum at base, with weak fovea; eyes almost flat. Antennae: reddish with dark brown club, inserted at middle of rostrum; scape moderately long, 5.0x longer than wide; funicle slightly longer than scape, segment 1 twice as long as wide, slightly stouter and slightly longer than segment 2 which is 1.5 as long as wide, segments 3–5 gradually more transverse; club short, oval, segment 1 almost glabrous. Pronotum: black, with dense and regular punctures, intervals between punctures narrow, smooth and shining, somewhat visible between recumbent to subrecumbent, moderately dense, greyish, long to very long (l/w 7–12), seta-like scales; moderately transverse (Pw/Pl 1.33), with weakly rounded sides, with moderately prominent apical constriction, widest at basal third, moderately convex. Elytra: blackish except a part of apical third, which is reddish; short (El/Ew 1.19), suboval, at base weakly concave, moderately wider than pronotum (Ew/Pw 1.26), with weakly rounded sides, widest at middle, somewhat convex on disc; interstriae somewhat visible between recumbent to suberect, moderately dense, greyish and light brown, long (1.5x longer than width of interstria; l/w 7– 12), seta-like scales, which are arranged in 1–2 irregular rows; striae moderately visible, one third narrower than interstriae, with a row of scales similar to the thinner ones covering interstriae. Legs: moderately stout, with recumbent to suberect, sparse, whitish, seta-like scales, which are distinctly shorter than width of tibia; femora blackish, clavate, profemora with big tooth ( Fig. 105 ), mesofemora with slightly smaller tooth and metafemora subdented; tibiae reddish, short, protibiae with apical part of ventral surface weakly directed outward ( Fig. 98 ); unci blackish, moderately stout; tarsi reddish, tarsomere 1 1.5x longer than wide, tarsomere 2 as long as wide, tarsomere 3 bilobed and distinctly wider than tarsomere 2, onychium almost as long as length of tarsomeres 1–3 taken together; claws blackish, equal in length, fused in basal half. Venter: metasternum black, clearly visible between subrecumbent, sparse, whitish, long, seta-like scales; mesothoracic epimera and meso- and metathoracic episterna covered densely with whitish, wide, fringed scales; abdomen black, with dense and regular punctures, which are clearly visible between subrecumbent, sparse, whitish, long, seta-like scales; ventrites length ratio: 1–2/ 3–4 2,02. Penis: fig. 108.

Female. As in male except rostrum distinctly longer (Rl/Pl 1.02) ( Fig. 44 ), thinner, smoother and shining, antennae inserted between basal third and median third of rostrum, all femora subdentate, unci of metatibiae smaller than others. Sternite 8: fig. 144. Spermatheca: fig. 157.

Variability. Length 1.3–1.8 mm. The elytra vary from completely reddish to almost completely black, except for a narrow apical part. The femora are also often reddish. The elytral pubescence is more or less erect and the shape of the pronotum is more or less subconical.

Remarks and comparative notes. It is one of the commonest species in the genus, without distinctive characters except for the stout femoral tooth in the male, which is also present only in M. crassifemur . This species is closely related to many species having short elytra—especially M. crassifemur , M. latiusculus , and M. ictericus , and others with longer elytra—such as M. ludyi and M. caucasicus (see comparative notes of these species).

Biological notes. This species lives on Plantago lanceolata L., where larvae feed on fruits and pupate in the floral spikes, without producing damage visible externally ( Hoffmann 1958).

Distribution. Europe, Caucasian States, Middle East, central Asia, Algeria ( Hoffmann 1958). Imported in northern America, Australia and New Zealand ( O'Brien & Wibmer 1982; Debinski & Holt 2000). Recently collected in South Africa ( Caldara et al. 2009).

Non-type specimens examined. About 1,200 specimens collected in Spain, France, United Kingdom, Italy, Germany, Czech Republic, Slovakia, Hungary, Poland, Sweden, Estonia, Russia, Armenia, Georgia, Croatia, Serbia, Republic of Macedonia, Greece, Bulgaria, Romania, Turkey, Syria, Israel, Kazakhstan, U.S.A., South Africa, Australia.

Figures

FIGURES 1–9. Habitus of (1) Mecinus pascuorum; (2) M. ictericus; (3) M. latiusculus; (4) M. caucasicus; (5) M. ludyi; (6) M. variabilis; (7) M. haemorrhoidalis; (8) M. seriatus; (9) M. sanctus. Not to the same scale.

FIGURES 43–57. Rostrum in lateral view of (43) Mecinus pascuorum, male; (44) idem, female; (45) M. ictericus, female; (46) M. caucasicus, male; (47) idem, female; (48) Mecinus variabilis, male; (49) idem, female; (50) M. haemorrhoidalis, male; (51) idem, female; (52) M. seriatus, female; (53) M. longulus, female; (54) M. tychioides, male; (55) M. labilis, male; (56) idem, female; (57) M. plantaginis, male. Scale bar = 0.5 mm.

FIGURES 98–107. Male right protibia in anterior view of (98) Mecinus pascuorum; (99) M. tanaiticus; (100) M. comosus; (101) M. simus; (102) M. pirazzolii; (103) M. vulpes; (104) M. pipistrellus. Male right profemur of (105) M. pascuorum; (106) M. ictericus. Right antenna of (107) M. paratychioides.

FIGURES 108–120. Penis in dorsal and lateral view of (108) Mecinus pascuorum; (109) M. crassifemur; (110) M. ictericus; (111) M. latiusculus; (112) M. caucasicus; (113) M. variabilis; (114) M. tychioides; (115) M. haemorrhoidalis; (116) M. longulus; (117) M. labilis; (118) M. plantaginis; (119) M. alboscutellatus alboscutellatus; (120) M. paratychioides. Scale bar = 0.2 mm.

FIGURES 144–156. Sternite 8 of (144) Mecinus pascuorum; (145) M. caucasicus; (146) M. marina; (147) M. reichei; (148) M. humeralis; (149) M. circulatus; (150) M. pyraster; (151) M. simus; (152) M. collaris; (153) M. janthinus; (154) M. lixoides; (155) M. sicardi; (156) M. heydenii. Scale bar = 0.2 mm.

FIGURES 157–171. Spermatheca of (157) Mecinus pascuorum; (158) M. caucasicus; (159) M. haemorrhoidalis; (160) M. labilis; (161) M. marina; (162) M. elongatus; (163) M. reichei; (164) M. circulatus; (165) M. pyraster; (166) M. simus; (167) M. comosus; (168) M. lixoides; (169) M. janthinus; (170) M. heydenii; (171) M. collaris. Scale bar = 0.2 mm.